A comparison of neuraxial block versus general anesthesia for elective total hip replacement: a meta-analysis.

BACKGROUND: A recent meta-analysis showed that compared with general anesthesia (GA), neuraxial block reduced many serious complications in patients undergoing various types of surgeries. It is not known whether this finding from studying heterogeneous patient groups is applicable to a particular surgical patient population. We performed the present meta-analysis to determine whether anesthesia choice affected the outcome after elective total hip replacement (THR).

METHODS: Medline (1966 to August 2005), MD Consult (1966 to August 2005), BIOSIS (1969 to August 2005), and EMBASE (1969 to August 2005) databases were searched. Randomized and quasi randomized studies comparing GA and neuraxial (spinal or epidural) block for elective THR were included in this analysis.

RESULTS: Ten independent trials, involving 330 patients under GA and 348 patients under neuraxial block, were identified and analyzed. Pooled results from five trials showed that neuraxial block significantly decreased the incidence of radiographically diagnosed deep venous thrombosis or pulmonary embolism. The odds ratio (OR) for deep venous thrombosis was 0.27 with 95% confidence interval (CI) 0.17-0.42. The OR for pulmonary embolism was 0.26 with 95% CI 0.12-0.56. Neuraxial block also decreased the operative time by 7.1 min/case (95% CI 2.3-11.9 min) and intraoperative blood loss by 275 mL/case (95% CI 180-371 mL). Data from three trials showed that patients under neuraxial block for THR were less likely to require blood transfusion than were patients under GA (21/177 = 12% vs 62/188 = 33% of patients transfused, P < 0.001 by z-test). The OR for this comparison was 0.26. However, the CIs were wide and compatible with both no effect and a nine-tenths reduction (95% CI 0.06-1.05).

CONCLUSIONS: Patients undergoing elective THR under neuraxial anesthesia seem to have better outcomes than those under GA.